本文選題：花生蛋白　切入點：凝膠　出處：《沈陽農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：近年來,以植物為主的食品及肉類替代品受到普遍關(guān)注�；ㄉ俏覈罹邍H競爭優(yōu)勢的出口農(nóng)產(chǎn)品之一,其以獨(dú)特的風(fēng)味和較高的營養(yǎng)價值被廣泛應(yīng)用于食品工業(yè)。目前,我國大部分花生用于制油,其副產(chǎn)物花生粕中的蛋白質(zhì)含量較高,但由于花生蛋白加工工藝的限制以及其功能性有待改善,花生粕的研究利用仍處于初級階段。蛋白凝膠具有較高的粘度、彈性和保水性,常作為穩(wěn)定劑或乳化劑應(yīng)用在肉制品、谷物制品以及乳制品等食品工業(yè)中。目前有關(guān)花生蛋白凝膠的研究不多,在現(xiàn)有的研究中,大多是經(jīng)高溫?zé)嵴T導(dǎo)或者輔以鹽類或酸類凝固劑形成的凝膠。研究表明,堿性蛋白酶具有促使蛋白質(zhì)形成交聯(lián)網(wǎng)絡(luò)結(jié)構(gòu)的能力,但是在不添加任何凝固劑的條件下,利用此方法制備成花生蛋白凝膠的研究還未見報道。本研究以低變性脫脂花生粕為原料,經(jīng)堿溶酸沉法提取花生分離蛋白,采用堿性蛋白酶對花生分離蛋白進(jìn)行限制性酶解,制備花生蛋白凝膠,研究花生蛋白凝膠的物化性質(zhì)及其結(jié)構(gòu)變化,并探討利用堿性蛋白酶限制性酶解制備花生蛋白凝膠的作用機(jī)理,研究結(jié)果如下:1.利用堿性蛋白酶對花生蛋白進(jìn)行限制性酶解,能夠使其在50℃～70℃的條件下形成凝膠,未經(jīng)酶解處理的花生蛋白溶液在70℃以內(nèi)無法形成凝膠。2.以花生蛋白凝膠的硬度為指標(biāo),通過單因素及響應(yīng)面試驗,得到制備花生蛋白凝膠的最佳工藝參數(shù)為:加酶量2.50 U/g,酶解溫度60℃,酶解時間36 min,pH 8.21,在此條件下制備的花生蛋白凝膠硬度的實測值為1.35±0.02N。3.對花生蛋白凝膠的物化性質(zhì)進(jìn)行分析。流變試驗、蠕變-恢復(fù)測試以及表觀粘度測試結(jié)果表明,該花生蛋白凝膠具有典型的凝膠流變特性;電泳分析顯示,經(jīng)酶解處理后,伴花生球蛋白Ⅱ所在的電泳條帶濃度顯著降低;DSC結(jié)果表明,經(jīng)酶解處理后,蛋白質(zhì)的熱穩(wěn)定性顯著升高,結(jié)構(gòu)的有序性顯著降低。4.對花生蛋白的二級結(jié)構(gòu)進(jìn)行分析。圓二色及紅外光譜分析表明,酶處理會顯著降低花生蛋白二級結(jié)構(gòu)中α-螺旋的含量,顯著增加β-折疊及無規(guī)則卷曲的含量,但對β-轉(zhuǎn)角含量的影響不顯著。5.對花生蛋白的三級結(jié)構(gòu)進(jìn)行分析。結(jié)果表明,花生蛋白凝膠形成的主要驅(qū)動力為疏水相互作用,其次為氫鍵,離子鍵不是主要的化學(xué)作用力;酶解后,花生蛋白的表面疏水性升高;熒光光譜的最大熒光波長發(fā)生紅移;暴露巰基和總巰基含量顯著增加,且兩者的比值增大,蛋白質(zhì)的解折疊程度增大。
[Abstract]:In recent years, plant-based food and meat substitutes have received widespread attention.Peanut is one of the most competitive international agricultural products in China. It is widely used in food industry with its unique flavor and high nutritional value.At present, most peanuts in China are used to make oil, and the protein content in peanut meal is high. However, due to the limitation of peanut protein processing technology and the improvement of its function, the research and utilization of peanut meal is still in the primary stage.Protein gels with high viscosity, elasticity and water retention are often used as stabilizers or emulsifiers in meat products, grain products, dairy products and other food industries.At present, there are few researches on peanut protein gel. In the present research, most of them are induced by high temperature heat or formed by salt or acid coagulant.The results show that alkaline protease has the ability to form cross-linking network structure of protein, but the preparation of peanut protein gel by this method without adding any coagulant has not been reported.In this study, peanut protein isolate was extracted from low denatured defatted peanut meal by alkaline lytic acid precipitation method. The protein was hydrolyzed by alkaline protease to prepare peanut protein gel.The physicochemical properties and structural changes of peanut protein gel were studied, and the mechanism of preparing peanut protein gel by alkaline protease restriction enzymatic hydrolysis was discussed. The results are as follows: 1.Using alkaline protease to hydrolyze peanut protein, it can form gel at 50 鈩，

本文編號：1702517